Transportation planning is a wide human-oriented field with diverse and challenging problems
waiting to be solved. Characteristics and performances of transport systems – services, costs,
infrastructures, vehicles and control systems are usually defined on the basis of quantitative
evaluation of their main effects. Most of the transport decisions take place under imprecision,
uncertainty and partial truth. Some objectives and constraints are often difficult to be measured by
crisp values. Traditional analytical techniques were found to be non-effective when dealing with
problems in which the dependencies between variables are too complex or ill-defined. Moreover,
hard computing models can not deal effectively with the transport decision-makers’ ambiguities
and uncertainties